Cancer, in one form or another, is a leading cause of death, and claimed the lives of more than 8.2 million people worldwide in 2012, according to the compiled statistics by WHO (WHO: http://www.who.int/mediacentre/factsheets/fs297/en/; retrieved on Sep. 6, 2015). It is estimated that the annual cancer cases will reach 22 millions by 2036. Although numerous cancer chemotherapeutics are available today, they often have very narrow therapeutic indices and very severe side effects. In addition, cancers can and often do develop resistance to many of these drugs. The fact that there currently are no drugs available that are capable of curing cancer diseases, the discovery and development of new anticancer drugs are very much needed and the undertaking of such studies is imperative.
Miliusanes is a group of compounds containing a substructure of oxo-spirodecane. A few patents have been published related to the compounds containing oxospirodecane or azaspirodecane or thiaspirocecane substructure (US 2009/0318548A1; US2011/021624A1 and WO2011098433A1).
In US 2009/0318548A1, the compounds of formula (VI) are synthesized. However, no anticancer data is reported in this patent.

In US2011/021624A1, the compounds of formula (VII) are synthesized. However, the representative compound is reported to show weak cytotoxicity against MDA-MB-435, HCT116, A549 and Hela cancer cells (IC50 values in the range of 17-42 μM).

In WO2011098433A1, the compounds of formula (VIII) are synthesized. The compounds have a chemical structure containing a biphenyl group, and are reported to have tumor inhibition activity by inhibiting fatty acid synthesis.

Thus, miliusanes compounds with more potent anticancer activity and low in toxicity are needed.
Citation or identification of any reference in this section or any other section of this application shall not be construed as an admission that such reference is available as prior art for the present application.